How much can we trust "lifetime" really?

I know quite a few people who bought lifetime versions of other password managers like 1pw, dashlane and more, just to a few years later they're faced with the amazing news that their lifetime purchase was actually "for a specific version of the app" and that they would have to pay subscriptions to get newer versions and updates. Over time they couldn't even use the old version due to software incompatibility and even security flaws.

So lifetime was more like a "6 year combo" or something.

Will this happen to proton? Has anybody read through the terms and conditions of that purchase?

Remember that companies can change attitudes in a matter of days if the leadership changes.